1. Field of the Invention
The present invention relates to a radiation curing silicone rubber composition, an adhesive silicone elastomer film that has been molded from the composition, a silicone elastomer film coated body using the adhesive silicone elastomer film, and structural body comprising an adhesive layer formed from said composition between substrates, and methods of producing the structural body.
2. Description of the Prior Art
Conventionally, epoxy-based adhesive films have been used for the die bonding of semiconductor devices, and for TAB tape bonding applications. However, these epoxy-based adhesive films display inadequate heat resistance and are not able to be converted to low elasticity forms (in other words, if for example, a highly elastic film is bonded as an adhesive layer between two different substrates, then the film tends to display poor thermal and mechanical stress relaxation properties, leading to a reduction in product reliability). In contrast, silicone-based adhesive films are typically highly heat resistant with low elasticity, but until now, silicone films with adequate adhesion and workability, which are also easy to produce, have remained elusive.
The applicants of the present invention have previously proposed an improved adhesive silicone elastomer film (see JP2000-234060A; U.S. counter part: U.S. Pat. No. 6,312,553), but under extreme conditions, such as a heat cycle test between −55° C. and 150° C., the adhesion was still somewhat inadequate, and peeling as a result of poor adhesion was observed on occasion. Furthermore, in JP2003-238808A and JP2003-238809A (their US counterpart: U.S. Ser. No. 10/366,357, i.e., US2003-0190484A), the time taken during die bonding for the required adhesion to manifest was problematic. Accordingly, a film in which adhesion manifests more rapidly during die bonding has been keenly sought. In addition, the preparation of adhesive silicone elastomer films requires advanced technology and expensive apparatus for the molding process, and accordingly, a simpler preparation has been keenly sought for the production of semiconductor products.